In this research, we studied a number of characteristics of two surface barrier detectors, one from LD and the other from PH, dedicated to detecting alpha particles. and comparing between characteristics of detectors. For the operating characteristic, we found that the optimal operating voltage of the LD detector is located in the range (1.35-1.4) volts, while of the PH detector was located in the range (0.9-1.35) volts. For the detection capability, we found that the LD detector is better than the PH detector, this is due to the presence thinner metal surface layer for LD detector.,